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2018-04-12tipc: fix unbalanced reference counterJon Maloy
When a topology subscription is created, we may encounter (or KASAN may provoke) a failure to create a corresponding service instance in the binding table. Instead of letting the tipc_nametbl_subscribe() report the failure back to the caller, the function just makes a warning printout and returns, without incrementing the subscription reference counter as expected by the caller. This makes the caller believe that the subscription was successful, so it will at a later moment try to unsubscribe the item. This involves a sub_put() call. Since the reference counter never was incremented in the first place, we get a premature delete of the subscription item, followed by a "use-after-free" warning. We fix this by adding a return value to tipc_nametbl_subscribe() and make the caller aware of the failure to subscribe. This bug seems to always have been around, but this fix only applies back to the commit shown below. Given the low risk of this happening we believe this to be sufficient. Fixes: commit 218527fe27ad ("tipc: replace name table service range array with rb tree") Reported-by: syzbot+aa245f26d42b8305d157@syzkaller.appspotmail.com Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-04tipc: Fix missing list initializations in struct tipc_subscriptionJon Maloy
When an item of struct tipc_subscription is created, we fail to initialize the two lists aggregated into the struct. This has so far never been a problem, since the items are just added to a root object by list_add(), which does not require the addee list to be pre-initialized. However, syzbot is provoking situations where this addition fails, whereupon the attempted removal if the item from the list causes a crash. This problem seems to always have been around, despite that the code for creating this object was rewritten in commit 242e82cc95f6 ("tipc: collapse subscription creation functions"), which is still in net-next. We fix this for that commit by initializing the two lists properly. Fixes: 242e82cc95f6 ("tipc: collapse subscription creation functions") Reported-by: syzbot+0bb443b74ce09197e970@syzkaller.appspotmail.com Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-02-16tipc: rename tipc_server to tipc_topsrvJon Maloy
We rename struct tipc_server to struct tipc_topsrv. This reflect its now specialized role as topology server. Accoringly, we change or add function prefixes to make it clearer which functionality those belong to. There are no functional changes in this commit. Acked-by: Ying.Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-02-16tipc: make struct tipc_server private for server.cJon Maloy
In order to narrow the interface and dependencies between the topology server and the subscription/binding table functionality we move struct tipc_server inside the file server.c. This requires some code adaptations in other files, but those are mostly minor. The most important change is that we have to move the start/stop functions for the topology server to server.c, where they logically belong anyway. Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-02-16tipc: some prefix changesJon Maloy
Since we now have removed struct tipc_subscriber from the code, and only struct tipc_subscription remains, there is no longer need for long and awkward prefixes to distinguish between their pertaining functions. We now change all tipc_subscrp_* prefixes to tipc_sub_*. This is a purely cosmetic change. Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-02-16tipc: collapse subscription creation functionsJon Maloy
After the previous changes it becomes logical to collapse the two-level creation of subscription instances into one. We do that here. We also rename the creation and deletion functions for more consistency. Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-02-16tipc: simplify endianness handling in topology subscriberJon Maloy
Because of the requirement for total distribution transparency, users send subscriptions and receive topology events in their own host format. It is up to the topology server to determine this format and do the correct conversions to and from its own host format when needed. Until now, this has been handled in a rather non-transparent way inside the topology server and subscriber code, leading to unnecessary complexity when creating subscriptions and issuing events. We now improve this situation by adding two new macros, tipc_sub_read() and tipc_evt_write(). Both those functions calculate the need for conversion internally before performing their respective operations. Hence, all handling of such conversions become transparent to the rest of the code. Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-02-16tipc: simplify interaction between subscription and topology connectionJon Maloy
The message transmission and reception in the topology server is more generic than is currently necessary. By basing the funtionality on the fact that we only send items of type struct tipc_event and always receive items of struct tipc_subcr we can make several simplifications, and also get rid of some unnecessary dynamic memory allocations. Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-02-16tipc: eliminate struct tipc_subscriberJon Maloy
It is unnecessary to keep two structures, struct tipc_conn and struct tipc_subscriber, with a one-to-one relationship and still with different life cycles. The fact that the two often run in different contexts, and still may access each other via direct pointers constitutes an additional hazard, something we have experienced at several occasions, and still see happening. We have identified at least two remaining problems that are easier to fix if we simplify the topology server data structure somewhat. - When there is a race between a subscription up/down event and a timeout event, it is fully possible that the former might be delivered after the latter, leading to confusion for the receiver. - The function tipc_subcrp_timeout() is executing in interrupt context, while the following call chain is at least theoretically possible: tipc_subscrp_timeout() tipc_subscrp_send_event() tipc_conn_sendmsg() conn_put() tipc_conn_kref_release() sock_release(sock) I.e., we end up calling a function that might try to sleep in interrupt context. To eliminate this, we need to ensure that the tipc_conn structure and the socket, as well as the subscription instances, only are deleted in work queue context, i.e., after the timeout event really has been sent out. We now remove this unnecessary complexity, by merging data and functionality of the subscriber structure into struct tipc_conn and the associated file server.c. We thereafter add a spinlock and a new 'inactive' state to the subscription structure. Using those, both problems described above can be easily solved. Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-02-16tipc: remove unnecessary function pointersJon Maloy
Interaction between the functionality in server.c and subscr.c is done via function pointers installed in struct server. This makes the code harder to follow, and doesn't serve any obvious purpose. Here, we replace the function pointers with direct function calls. Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-02-16tipc: remove redundant code in topology serverJon Maloy
The socket handling in the topology server is unnecessarily generic. It is prepared to handle both SOCK_RDM, SOCK_DGRAM and SOCK_STREAM type sockets, as well as the only socket type which is really used, SOCK_SEQPACKET. We now remove this redundant code to make the code more readable. Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-16tipc: fix race condition at topology server receiveJon Maloy
We have identified a race condition during reception of socket events and messages in the topology server. - The function tipc_close_conn() is releasing the corresponding struct tipc_subscriber instance without considering that there may still be items in the receive work queue. When those are scheduled, in the function tipc_receive_from_work(), they are using the subscriber pointer stored in struct tipc_conn, without first checking if this is valid or not. This will sometimes lead to crashes, as the next call of tipc_conn_recvmsg() will access the now deleted item. We fix this by making the usage of this pointer conditional on whether the connection is active or not. I.e., we check the condition test_bit(CF_CONNECTED) before making the call tipc_conn_recvmsg(). - Since the two functions may be running on different cores, the condition test described above is not enough. tipc_close_conn() may come in between and delete the subscriber item after the condition test is done, but before tipc_conn_recv_msg() is finished. This happens less frequently than the problem described above, but leads to the same symptoms. We fix this by using the existing sk_callback_lock for mutual exclusion in the two functions. In addition, we have to move a call to tipc_conn_terminate() outside the mentioned lock to avoid deadlock. Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-09tipc: improve groupcast scope handlingJon Maloy
When a member joins a group, it also indicates a binding scope. This makes it possible to create both node local groups, invisible to other nodes, as well as cluster global groups, visible everywhere. In order to avoid that different members end up having permanently differing views of group size and memberhip, we must inhibit locally and globally bound members from joining the same group. We do this by using the binding scope as an additional separator between groups. I.e., a member must ignore all membership events from sockets using a different scope than itself, and all lookups for message destinations must require an exact match between the message's lookup scope and the potential target's binding scope. Apart from making it possible to create local groups using the same identity on different nodes, a side effect of this is that it now also becomes possible to create a cluster global group with the same identity across the same nodes, without interfering with the local groups. Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-09tipc: add option to suppress PUBLISH events for pre-existing publicationsJon Maloy
Currently, when a user is subscribing for binding table publications, he will receive a PUBLISH event for all already existing matching items in the binding table. However, a group socket making a subscriptions doesn't need this initial status update from the binding table, because it has already scanned it during the join operation. Worse, the multiplicatory effect of issuing mutual events for dozens or hundreds group members within a short time frame put a heavy load on the topology server, with the end result that scale out operations on a big group tend to take much longer than needed. We now add a new filter option, TIPC_SUB_NO_STATUS, for topology server subscriptions, so that this initial avalanche of events is suppressed. This change, along with the previous commit, significantly improves the range and speed of group scale out operations. We keep the new option internal for the tipc driver, at least for now. Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-01net: tipc: Convert timers to use timer_setup()Kees Cook
In preparation for unconditionally passing the struct timer_list pointer to all timer callbacks, switch to using the new timer_setup() and from_timer() to pass the timer pointer explicitly. Cc: Jon Maloy <jon.maloy@ericsson.com> Cc: Ying Xue <ying.xue@windriver.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: netdev@vger.kernel.org Cc: tipc-discussion@lists.sourceforge.net Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-22tipc: fix a race condition of releasing subscriber objectYing Xue
No matter whether a request is inserted into workqueue as a work item to cancel a subscription or to delete a subscription's subscriber asynchronously, the work items may be executed in different workers. As a result, it doesn't mean that one request which is raised prior to another request is definitely handled before the latter. By contrast, if the latter request is executed before the former request, below error may happen: [ 656.183644] BUG: spinlock bad magic on CPU#0, kworker/u8:0/12117 [ 656.184487] general protection fault: 0000 [#1] SMP [ 656.185160] Modules linked in: tipc ip6_udp_tunnel udp_tunnel 9pnet_virtio 9p 9pnet virtio_net virtio_pci virtio_ring virtio [last unloaded: ip6_udp_tunnel] [ 656.187003] CPU: 0 PID: 12117 Comm: kworker/u8:0 Not tainted 4.11.0-rc7+ #6 [ 656.187920] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 [ 656.188690] Workqueue: tipc_rcv tipc_recv_work [tipc] [ 656.189371] task: ffff88003f5cec40 task.stack: ffffc90004448000 [ 656.190157] RIP: 0010:spin_bug+0xdd/0xf0 [ 656.190678] RSP: 0018:ffffc9000444bcb8 EFLAGS: 00010202 [ 656.191375] RAX: 0000000000000034 RBX: ffff88003f8d1388 RCX: 0000000000000000 [ 656.192321] RDX: ffff88003ba13708 RSI: ffff88003ba0cd08 RDI: ffff88003ba0cd08 [ 656.193265] RBP: ffffc9000444bcd0 R08: 0000000000000030 R09: 000000006b6b6b6b [ 656.194208] R10: ffff8800bde3e000 R11: 00000000000001b4 R12: 6b6b6b6b6b6b6b6b [ 656.195157] R13: ffffffff81a3ca64 R14: ffff88003f8d1388 R15: ffff88003f8d13a0 [ 656.196101] FS: 0000000000000000(0000) GS:ffff88003ba00000(0000) knlGS:0000000000000000 [ 656.197172] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 656.197935] CR2: 00007f0b3d2e6000 CR3: 000000003ef9e000 CR4: 00000000000006f0 [ 656.198873] Call Trace: [ 656.199210] do_raw_spin_lock+0x66/0xa0 [ 656.199735] _raw_spin_lock_bh+0x19/0x20 [ 656.200258] tipc_subscrb_subscrp_delete+0x28/0xf0 [tipc] [ 656.200990] tipc_subscrb_rcv_cb+0x45/0x260 [tipc] [ 656.201632] tipc_receive_from_sock+0xaf/0x100 [tipc] [ 656.202299] tipc_recv_work+0x2b/0x60 [tipc] [ 656.202872] process_one_work+0x157/0x420 [ 656.203404] worker_thread+0x69/0x4c0 [ 656.203898] kthread+0x138/0x170 [ 656.204328] ? process_one_work+0x420/0x420 [ 656.204889] ? kthread_create_on_node+0x40/0x40 [ 656.205527] ret_from_fork+0x29/0x40 [ 656.206012] Code: 48 8b 0c 25 00 c5 00 00 48 c7 c7 f0 24 a3 81 48 81 c1 f0 05 00 00 65 8b 15 61 ef f5 7e e8 9a 4c 09 00 4d 85 e4 44 8b 4b 08 74 92 <45> 8b 84 24 40 04 00 00 49 8d 8c 24 f0 05 00 00 eb 8d 90 0f 1f [ 656.208504] RIP: spin_bug+0xdd/0xf0 RSP: ffffc9000444bcb8 [ 656.209798] ---[ end trace e2a800e6eb0770be ]--- In above scenario, the request of deleting subscriber was performed earlier than the request of canceling a subscription although the latter was issued before the former, which means tipc_subscrb_delete() was called before tipc_subscrp_cancel(). As a result, when tipc_subscrb_subscrp_delete() called by tipc_subscrp_cancel() was executed to cancel a subscription, the subscription's subscriber refcnt had been decreased to 1. After tipc_subscrp_delete() where the subscriber was freed because its refcnt was decremented to zero, but the subscriber's lock had to be released, as a consequence, panic happened. By contrast, if we increase subscriber's refcnt before tipc_subscrb_subscrp_delete() is called in tipc_subscrp_cancel(), the panic issue can be avoided. Fixes: d094c4d5f5c7 ("tipc: add subscription refcount to avoid invalid delete") Reported-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com> Signed-off-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-22tipc: remove subscription references only for pending timersParthasarathy Bhuvaragan
In commit, 139bb36f754a ("tipc: advance the time of deleting subscription from subscriber->subscrp_list"), we delete the subscription from the subscribers list and from nametable unconditionally. This leads to the following bug if the timer running tipc_subscrp_timeout() in another CPU accesses the subscription list after the subscription delete request. [39.570] general protection fault: 0000 [#1] SMP :: [39.574] task: ffffffff81c10540 task.stack: ffffffff81c00000 [39.575] RIP: 0010:tipc_subscrp_timeout+0x32/0x80 [tipc] [39.576] RSP: 0018:ffff88003ba03e90 EFLAGS: 00010282 [39.576] RAX: dead000000000200 RBX: ffff88003f0f3600 RCX: 0000000000000101 [39.577] RDX: dead000000000100 RSI: 0000000000000201 RDI: ffff88003f0d7948 [39.578] RBP: ffff88003ba03ea0 R08: 0000000000000001 R09: ffff88003ba03ef8 [39.579] R10: 000000000000014f R11: 0000000000000000 R12: ffff88003f0d7948 [39.580] R13: ffff88003f0f3618 R14: ffffffffa006c250 R15: ffff88003f0f3600 [39.581] FS: 0000000000000000(0000) GS:ffff88003ba00000(0000) knlGS:0000000000000000 [39.582] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [39.583] CR2: 00007f831c6e0714 CR3: 000000003d3b0000 CR4: 00000000000006f0 [39.584] Call Trace: [39.584] <IRQ> [39.585] call_timer_fn+0x3d/0x180 [39.585] ? tipc_subscrb_rcv_cb+0x260/0x260 [tipc] [39.586] run_timer_softirq+0x168/0x1f0 [39.586] ? sched_clock_cpu+0x16/0xc0 [39.587] __do_softirq+0x9b/0x2de [39.587] irq_exit+0x60/0x70 [39.588] smp_apic_timer_interrupt+0x3d/0x50 [39.588] apic_timer_interrupt+0x86/0x90 [39.589] RIP: 0010:default_idle+0x20/0xf0 [39.589] RSP: 0018:ffffffff81c03e58 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff10 [39.590] RAX: 0000000000000000 RBX: ffffffff81c10540 RCX: 0000000000000000 [39.591] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 [39.592] RBP: ffffffff81c03e68 R08: 0000000000000000 R09: 0000000000000000 [39.593] R10: ffffc90001cbbe00 R11: 0000000000000000 R12: 0000000000000000 [39.594] R13: ffffffff81c10540 R14: 0000000000000000 R15: 0000000000000000 [39.595] </IRQ> :: [39.603] RIP: tipc_subscrp_timeout+0x32/0x80 [tipc] RSP: ffff88003ba03e90 [39.604] ---[ end trace 79ce94b7216cb459 ]--- Fixes: 139bb36f754a ("tipc: advance the time of deleting subscription from subscriber->subscrp_list") Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-28tipc: adjust the policy of holding subscription krefYing Xue
When a new subscription object is inserted into name_seq->subscriptions list, it's under name_seq->lock protection; when a subscription is deleted from the list, it's also under the same lock protection; similarly, when accessing a subscription by going through subscriptions list, the entire process is also protected by the name_seq->lock. Therefore, if subscription refcount is increased before it's inserted into subscriptions list, and its refcount is decreased after it's deleted from the list, it will be unnecessary to hold refcount at all before accessing subscription object which is obtained by going through subscriptions list under name_seq->lock protection. Signed-off-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-28tipc: advance the time of deleting subscription from subscriber->subscrp_listYing Xue
After a subscription object is created, it's inserted into its subscriber subscrp_list list under subscriber lock protection, similarly, before it's destroyed, it should be first removed from its subscriber->subscrp_list. Since the subscription list is accessed with subscriber lock, all the subscriptions are valid during the lock duration. Hence in tipc_subscrb_subscrp_delete(), we remove subscription get/put and the extra subscriber unlock/lock. After this change, the subscriptions refcount cleanup is very simple and does not access any lock. Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-22tipc: fix nametbl deadlock at tipc_nametbl_unsubscribeYing Xue
Until now, tipc_nametbl_unsubscribe() is called at subscriptions reference count cleanup. Usually the subscriptions cleanup is called at subscription timeout or at subscription cancel or at subscriber delete. We have ignored the possibility of this being called from other locations, which causes deadlock as we try to grab the tn->nametbl_lock while holding it already. CPU1: CPU2: ---------- ---------------- tipc_nametbl_publish spin_lock_bh(&tn->nametbl_lock) tipc_nametbl_insert_publ tipc_nameseq_insert_publ tipc_subscrp_report_overlap tipc_subscrp_get tipc_subscrp_send_event tipc_close_conn tipc_subscrb_release_cb tipc_subscrb_delete tipc_subscrp_put tipc_subscrp_put tipc_subscrp_kref_release tipc_nametbl_unsubscribe spin_lock_bh(&tn->nametbl_lock) <<grab nametbl_lock again>> CPU1: CPU2: ---------- ---------------- tipc_nametbl_stop spin_lock_bh(&tn->nametbl_lock) tipc_purge_publications tipc_nameseq_remove_publ tipc_subscrp_report_overlap tipc_subscrp_get tipc_subscrp_send_event tipc_close_conn tipc_subscrb_release_cb tipc_subscrb_delete tipc_subscrp_put tipc_subscrp_put tipc_subscrp_kref_release tipc_nametbl_unsubscribe spin_lock_bh(&tn->nametbl_lock) <<grab nametbl_lock again>> In this commit, we advance the calling of tipc_nametbl_unsubscribe() from the refcount cleanup to the intended callers. Fixes: d094c4d5f5c7 ("tipc: add subscription refcount to avoid invalid delete") Reported-by: John Thompson <thompa.atl@gmail.com> Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-24tipc: add subscription refcount to avoid invalid deleteParthasarathy Bhuvaragan
Until now, the subscribers keep track of the subscriptions using reference count at subscriber level. At subscription cancel or subscriber delete, we delete the subscription only if the timer was pending for the subscription. This approach is incorrect as: 1. del_timer() is not SMP safe, if on CPU0 the check for pending timer returns true but CPU1 might schedule the timer callback thereby deleting the subscription. Thus when CPU0 is scheduled, it deletes an invalid subscription. 2. We export tipc_subscrp_report_overlap(), which accesses the subscription pointer multiple times. Meanwhile the subscription timer can expire thereby freeing the subscription and we might continue to access the subscription pointer leading to memory violations. In this commit, we introduce subscription refcount to avoid deleting an invalid subscription. Reported-and-Tested-by: John Thompson <thompa.atl@gmail.com> Acked-by: Ying Xue <ying.xue@windriver.com> Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-28tipc: remove an unnecessary NULL checkDan Carpenter
This is never called with a NULL "buf" and anyway, we dereference 's' on the lines before so it would Oops before we reach the check. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-14tipc: fix a race condition leading to subscriber refcnt bugParthasarathy Bhuvaragan
Until now, the requests sent to topology server are queued to a workqueue by the generic server framework. These messages are processed by worker threads and trigger the registered callbacks. To reduce latency on uniprocessor systems, explicit rescheduling is performed using cond_resched() after MAX_RECV_MSG_COUNT(25) messages. This implementation on SMP systems leads to an subscriber refcnt error as described below: When a worker thread yields by calling cond_resched() in a SMP system, a new worker is created on another CPU to process the pending workitem. Sometimes the sleeping thread wakes up before the new thread finishes execution. This breaks the assumption on ordering and being single threaded. The fault is more frequent when MAX_RECV_MSG_COUNT is lowered. If the first thread was processing subscription create and the second thread processing close(), the close request will free the subscriber and the create request oops as follows: [31.224137] WARNING: CPU: 2 PID: 266 at include/linux/kref.h:46 tipc_subscrb_rcv_cb+0x317/0x380 [tipc] [31.228143] CPU: 2 PID: 266 Comm: kworker/u8:1 Not tainted 4.5.0+ #97 [31.228377] Workqueue: tipc_rcv tipc_recv_work [tipc] [...] [31.228377] Call Trace: [31.228377] [<ffffffff812fbb6b>] dump_stack+0x4d/0x72 [31.228377] [<ffffffff8105a311>] __warn+0xd1/0xf0 [31.228377] [<ffffffff8105a3fd>] warn_slowpath_null+0x1d/0x20 [31.228377] [<ffffffffa0098067>] tipc_subscrb_rcv_cb+0x317/0x380 [tipc] [31.228377] [<ffffffffa00a4984>] tipc_receive_from_sock+0xd4/0x130 [tipc] [31.228377] [<ffffffffa00a439b>] tipc_recv_work+0x2b/0x50 [tipc] [31.228377] [<ffffffff81071925>] process_one_work+0x145/0x3d0 [31.246554] ---[ end trace c3882c9baa05a4fd ]--- [31.248327] BUG: spinlock bad magic on CPU#2, kworker/u8:1/266 [31.249119] BUG: unable to handle kernel NULL pointer dereference at 0000000000000428 [31.249323] IP: [<ffffffff81099d0c>] spin_dump+0x5c/0xe0 [31.249323] PGD 0 [31.249323] Oops: 0000 [#1] SMP In this commit, we - rename tipc_conn_shutdown() to tipc_conn_release(). - move connection release callback execution from tipc_close_conn() to a new function tipc_sock_release(), which is executed before we free the connection. Thus we release the subscriber during connection release procedure rather than connection shutdown procedure. Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com> Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-08Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Several cases of overlapping changes, as well as one instance (vxlan) of a bug fix in 'net' overlapping with code movement in 'net-next'. Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-06tipc: fix nullptr crash during subscription cancelParthasarathy Bhuvaragan
commit 4d5cfcba2f6e ('tipc: fix connection abort during subscription cancel'), removes the check for a valid subscription before calling tipc_nametbl_subscribe(). This will lead to a nullptr exception when we process a subscription cancel request. For a cancel request, a null subscription is passed to tipc_nametbl_subscribe() resulting in exception. In this commit, we call tipc_nametbl_subscribe() only for a valid subscription. Fixes: 4d5cfcba2f6e ('tipc: fix connection abort during subscription cancel') Reported-by: Anders Widell <anders.widell@ericsson.com> Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com> Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-06tipc: donot create timers if subscription timeout = TIPC_WAIT_FOREVERParthasarathy Bhuvaragan
Until now, we create timers even for the subscription requests with timeout = TIPC_WAIT_FOREVER. This can be improved by avoiding timer creation when the timeout is set to TIPC_WAIT_FOREVER. In this commit, we introduce a check to creates timers only when timeout != TIPC_WAIT_FOREVER. Acked-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-06tipc: protect tipc_subscrb_get() with subscriber spin lockParthasarathy Bhuvaragan
Until now, during subscription creation the mod_time() & tipc_subscrb_get() are called after releasing the subscriber spin lock. In a SMP system when performing a subscription creation, if the subscription timeout occurs simultaneously (the timer is scheduled to run on another CPU) then the timer thread might decrement the subscribers refcount before the create thread increments the refcount. This can be simulated by creating subscription with timeout=0 and sometimes the timeout occurs before the create request is complete. This leads to the following message: [30.702949] BUG: spinlock bad magic on CPU#1, kworker/u8:3/87 [30.703834] general protection fault: 0000 [#1] SMP [30.704826] CPU: 1 PID: 87 Comm: kworker/u8:3 Not tainted 4.4.0-rc8+ #18 [30.704826] Workqueue: tipc_rcv tipc_recv_work [tipc] [30.704826] task: ffff88003f878600 ti: ffff88003fae0000 task.ti: ffff88003fae0000 [30.704826] RIP: 0010:[<ffffffff8109196c>] [<ffffffff8109196c>] spin_dump+0x5c/0xe0 [...] [30.704826] Call Trace: [30.704826] [<ffffffff81091a16>] spin_bug+0x26/0x30 [30.704826] [<ffffffff81091b75>] do_raw_spin_lock+0xe5/0x120 [30.704826] [<ffffffff81684439>] _raw_spin_lock_bh+0x19/0x20 [30.704826] [<ffffffffa0096f10>] tipc_subscrb_rcv_cb+0x1d0/0x330 [tipc] [30.704826] [<ffffffffa00a37b1>] tipc_receive_from_sock+0xc1/0x150 [tipc] [30.704826] [<ffffffffa00a31df>] tipc_recv_work+0x3f/0x80 [tipc] [30.704826] [<ffffffff8106a739>] process_one_work+0x149/0x3c0 [30.704826] [<ffffffff8106aa16>] worker_thread+0x66/0x460 [30.704826] [<ffffffff8106a9b0>] ? process_one_work+0x3c0/0x3c0 [30.704826] [<ffffffff8106a9b0>] ? process_one_work+0x3c0/0x3c0 [30.704826] [<ffffffff8107029d>] kthread+0xed/0x110 [30.704826] [<ffffffff810701b0>] ? kthread_create_on_node+0x190/0x190 [30.704826] [<ffffffff81684bdf>] ret_from_fork+0x3f/0x70 In this commit, 1. we remove the check for the return code for mod_timer() 2. we protect tipc_subscrb_get() using the subscriber spin lock. We increment the subscriber's refcount as soon as we add the subscription to subscriber's subscription list. Acked-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-06tipc: hold subscriber->lock for tipc_nametbl_subscribe()Parthasarathy Bhuvaragan
Until now, while creating a subscription the subscriber lock protects only the subscribers subscription list and not the nametable. The call to tipc_nametbl_subscribe() is outside the lock. However, at subscription timeout and cancel both the subscribers subscription list and the nametable are protected by the subscriber lock. This asymmetric locking mechanism leads to the following problem: In a SMP system, the timer can be fire on another core before the create request is complete. When the timer thread calls tipc_nametbl_unsubscribe() before create thread calls tipc_nametbl_subscribe(), we get a nullptr exception. This can be simulated by creating subscription with timeout=0 and sometimes the timeout occurs before the create request is complete. The following is the oops: [57.569661] BUG: unable to handle kernel NULL pointer dereference at (null) [57.577498] IP: [<ffffffffa02135aa>] tipc_nametbl_unsubscribe+0x8a/0x120 [tipc] [57.584820] PGD 0 [57.586834] Oops: 0002 [#1] SMP [57.685506] CPU: 14 PID: 10077 Comm: kworker/u40:1 Tainted: P OENX 3.12.48-52.27.1. 9688.1.PTF-default #1 [57.703637] Workqueue: tipc_rcv tipc_recv_work [tipc] [57.708697] task: ffff88064c7f00c0 ti: ffff880629ef4000 task.ti: ffff880629ef4000 [57.716181] RIP: 0010:[<ffffffffa02135aa>] [<ffffffffa02135aa>] tipc_nametbl_unsubscribe+0x8a/ 0x120 [tipc] [...] [57.812327] Call Trace: [57.814806] [<ffffffffa0211c77>] tipc_subscrp_delete+0x37/0x90 [tipc] [57.821357] [<ffffffffa0211e2f>] tipc_subscrp_timeout+0x3f/0x70 [tipc] [57.827982] [<ffffffff810618c1>] call_timer_fn+0x31/0x100 [57.833490] [<ffffffff81062709>] run_timer_softirq+0x1f9/0x2b0 [57.839414] [<ffffffff8105a795>] __do_softirq+0xe5/0x230 [57.844827] [<ffffffff81520d1c>] call_softirq+0x1c/0x30 [57.850150] [<ffffffff81004665>] do_softirq+0x55/0x90 [57.855285] [<ffffffff8105aa35>] irq_exit+0x95/0xa0 [57.860290] [<ffffffff815215b5>] smp_apic_timer_interrupt+0x45/0x60 [57.866644] [<ffffffff8152005d>] apic_timer_interrupt+0x6d/0x80 [57.872686] [<ffffffffa02121c5>] tipc_subscrb_rcv_cb+0x2a5/0x3f0 [tipc] [57.879425] [<ffffffffa021c65f>] tipc_receive_from_sock+0x9f/0x100 [tipc] [57.886324] [<ffffffffa021c826>] tipc_recv_work+0x26/0x60 [tipc] [57.892463] [<ffffffff8106fb22>] process_one_work+0x172/0x420 [57.898309] [<ffffffff8107079a>] worker_thread+0x11a/0x3c0 [57.903871] [<ffffffff81077114>] kthread+0xb4/0xc0 [57.908751] [<ffffffff8151f318>] ret_from_fork+0x58/0x90 In this commit, we do the following at subscription creation: 1. set the subscription's subscriber pointer before performing tipc_nametbl_subscribe(), as this value is required further in the call chain ex: by tipc_subscrp_send_event(). 2. move tipc_nametbl_subscribe() under the scope of subscriber lock Acked-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-06tipc: fix connection abort when receiving invalid cancel requestParthasarathy Bhuvaragan
Until now, the subscribers endianness for a subscription create/cancel request is determined as: swap = !(s->filter & (TIPC_SUB_PORTS | TIPC_SUB_SERVICE)) The checks are performed only for port/service subscriptions. The swap calculation is incorrect if the filter in the subscription cancellation request is set to TIPC_SUB_CANCEL (it's a malformed cancel request, as the corresponding subscription create filter is missing). Thus, the check if the request is for cancellation fails and the request is treated as a subscription create request. The subscription creation fails as the request is illegal, which terminates this connection. In this commit we determine the endianness by including TIPC_SUB_CANCEL, which will set swap correctly and the request is processed as a cancellation request. Acked-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-06tipc: fix connection abort during subscription cancellationParthasarathy Bhuvaragan
In 'commit 7fe8097cef5f ("tipc: fix nullpointer bug when subscribing to events")', we terminate the connection if the subscription creation fails. In the same commit, the subscription creation result was based on the value of subscription pointer (set in the function) instead of the return code. Unfortunately, the same function also handles subscription cancellation request. For a subscription cancellation request, the subscription pointer cannot be set. Thus the connection is terminated during cancellation request. In this commit, we move the subcription cancel check outside of tipc_subscrp_create(). Hence, - tipc_subscrp_create() will create a subscripton - tipc_subscrb_rcv_cb() will subscribe or cancel a subscription. Fixes: 'commit 7fe8097cef5f ("tipc: fix nullpointer bug when subscribing to events")' Acked-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-06tipc: introduce tipc_subscrb_subscribe() routineParthasarathy Bhuvaragan
In this commit, we split tipc_subscrp_create() into two: 1. tipc_subscrp_create() creates a subscription 2. A new function tipc_subscrp_subscribe() adds the subscription to the subscriber subscription list, activates the subscription timer and subscribes to the nametable updates. In future commits, the purpose of tipc_subscrb_rcv_cb() will be to either subscribe or cancel a subscription. There is no functional change in this commit. Acked-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-06tipc: remove struct tipc_name_seq from struct tipc_subscriptionParthasarathy Bhuvaragan
Until now, struct tipc_subscriber has duplicate fields for type, upper and lower (as member of struct tipc_name_seq) at: 1. as member seq in struct tipc_subscription 2. as member seq in struct tipc_subscr, which is contained in struct tipc_event The former structure contains the type, upper and lower values in network byte order and the later contains the intact copy of the request. The struct tipc_subscription contains a field swap to determine if request needs network byte order conversion. Thus by using swap, we can convert the request when required instead of duplicating it. In this commit, 1. we remove the references to these elements as members of struct tipc_subscription and replace them with elements from struct tipc_subscr. 2. provide new functions to convert the user request into network byte order. Acked-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-06tipc: remove filter and timeout elements from struct tipc_subscriptionParthasarathy Bhuvaragan
Until now, struct tipc_subscription has duplicate timeout and filter attributes present: 1. directly as members of struct tipc_subscription 2. in struct tipc_subscr, which is contained in struct tipc_event In this commit, we remove the references to these elements as members of struct tipc_subscription and replace them with elements from struct tipc_subscr. Acked-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-06tipc: remove incorrect check for subscription timeout valueParthasarathy Bhuvaragan
Until now, during subscription creation we set sub->timeout by converting the timeout request value in milliseconds to jiffies. This is followed by setting the timeout value in the timer if sub->timeout != TIPC_WAIT_FOREVER. For a subscription create request with a timeout value of TIPC_WAIT_FOREVER, msecs_to_jiffies(TIPC_WAIT_FOREVER) returns MAX_JIFFY_OFFSET (0xfffffffe). This is not equal to TIPC_WAIT_FOREVER (0xffffffff). In this commit, we remove this check. Acked-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-01-29tipc: fix connection abort during subscription cancelParthasarathy Bhuvaragan
In 'commit 7fe8097cef5f ("tipc: fix nullpointer bug when subscribing to events")', we terminate the connection if the subscription creation fails. In the same commit, the subscription creation result was based on the value of the subscription pointer (set in the function) instead of the return code. Unfortunately, the same function tipc_subscrp_create() handles subscription cancel request. For a subscription cancellation request, the subscription pointer cannot be set. Thus if a subscriber has several subscriptions and cancels any of them, the connection is terminated. In this commit, we terminate the connection based on the return value of tipc_subscrp_create(). Fixes: commit 7fe8097cef5f ("tipc: fix nullpointer bug when subscribing to events") Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-04tipc: adjust locking policy of subscriptionYing Xue
Currently subscriber's lock protects not only subscriber's subscription list but also all subscriptions linked into the list. However, as all members of subscription are never changed after they are initialized, it's unnecessary for subscription to be protected under subscriber's lock. If the lock is used to only protect subscriber's subscription list, the adjustment not only makes the locking policy simpler, but also helps to avoid a deadlock which may happen once creating a subscription is failed. Signed-off-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Jon Maloy <jon.maloy@ericson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-04tipc: involve reference counter for subscriberYing Xue
At present subscriber's lock is used to protect the subscription list of subscriber as well as subscriptions linked into the list. While one or all subscriptions are deleted through iterating the list, the subscriber's lock must be held. Meanwhile, as deletion of subscription may happen in subscription timer's handler, the lock must be grabbed in the function as well. When subscription's timer is terminated with del_timer_sync() during above iteration, subscriber's lock has to be temporarily released, otherwise, deadlock may occur. However, the temporary release may cause the double free of a subscription as the subscription is not disconnected from the subscription list. Now if a reference counter is introduced to subscriber, subscription's timer can be asynchronously stopped with del_timer(). As a result, the issue is not only able to be fixed, but also relevant code is pretty readable and understandable. Signed-off-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Jon Maloy <jon.maloy@ericson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-04tipc: introduce tipc_subscrb_create routineYing Xue
Introducing a new function makes the purpose of tipc_subscrb_connect_cb callback routine more clear. Signed-off-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Jon Maloy <jon.maloy@ericson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-04tipc: rename functions defined in subscr.cYing Xue
When a topology server accepts a connection request from its client, it allocates a connection instance and a tipc_subscriber structure object. The former is used to communicate with client, and the latter is often treated as a subscriber which manages all subscription events requested from a same client. When a topology server receives a request of subscribing name services from a client through the connection, it creates a tipc_subscription structure instance which is seen as a subscription recording what name services are subscribed. In order to manage all subscriptions from a same client, topology server links them into the subscrp_list of the subscriber. So subscriber and subscription completely represents different meanings respectively, but function names associated with them make us so confused that we are unable to easily tell which function is against subscriber and which is to subscription. So we want to eliminate the confusion by renaming them. Signed-off-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Jon Maloy <jon.maloy@ericson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-02-27tipc: fix nullpointer bug when subscribing to eventsErik Hugne
If a subscription request is sent to a topology server connection, and any error occurs (malformed request, oom or limit reached) while processing this request, TIPC should terminate the subscriber connection. While doing so, it tries to access fields in an already freed (or never allocated) subscription element leading to a nullpointer exception. We fix this by removing the subscr_terminate function and terminate the connection immediately upon any subscription failure. Signed-off-by: Erik Hugne <erik.hugne@ericsson.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-01-12tipc: make subscriber server support net namespaceYing Xue
TIPC establishes one subscriber server which allows users to subscribe their interesting name service status. After tipc supports namespace, one dedicated tipc stack instance is created for each namespace, and each instance can be deemed as one independent TIPC node. As a result, subscriber server must be built for each namespace. Signed-off-by: Ying Xue <ying.xue@windriver.com> Tested-by: Tero Aho <Tero.Aho@coriant.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-01-12tipc: name tipc name table support net namespaceYing Xue
TIPC name table is used to store the mapping relationship between TIPC service name and socket port ID. When tipc supports namespace, it allows users to publish service names only owned by a certain namespace. Therefore, every namespace must have its private name table to prevent service names published to one namespace from being contaminated by other service names in another namespace. Therefore, The name table global variable (ie, nametbl) and its lock must be moved to tipc_net structure, and a parameter of namespace must be added for necessary functions so that they can obtain name table variable defined in tipc_net structure. Signed-off-by: Ying Xue <ying.xue@windriver.com> Tested-by: Tero Aho <Tero.Aho@coriant.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-01-12tipc: remove unnecessary wrapper functions of kernel timer APIsYing Xue
Not only some wrapper function like k_term_timer() is empty, but also some others including k_start_timer() and k_cancel_timer() don't return back any value to its caller, what's more, there is no any component in the kernel world to do such thing. Therefore, these timer interfaces defined in tipc module should be purged. Signed-off-by: Ying Xue <ying.xue@windriver.com> Tested-by: Tero Aho <Tero.Aho@coriant.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-12-08tipc: remove unnecessary INIT_LIST_HEADYing Xue
When a list_head variable is seen as a new entry to be added to a list head, it's unnecessary to be initialized with INIT_LIST_HEAD(). Signed-off-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Tested-by: Erik Hugne <erik.hugne@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-23tipc: remove include file port.hJon Paul Maloy
We move the inline functions in the file port.h to socket.c, and modify their names accordingly. We move struct tipc_port and some macros to socket.h. Finally, we remove the file port.h. Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Reviewed-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-03-24tipc: fix spinlock recursion bug for failed subscriptionsErik Hugne
If a topology event subscription fails for any reason, such as out of memory, max number reached or because we received an invalid request the correct behavior is to terminate the subscribers connection to the topology server. This is currently broken and produces the following oops: [27.953662] tipc: Subscription rejected, illegal request [27.955329] BUG: spinlock recursion on CPU#1, kworker/u4:0/6 [27.957066] lock: 0xffff88003c67f408, .magic: dead4ead, .owner: kworker/u4:0/6, .owner_cpu: 1 [27.958054] CPU: 1 PID: 6 Comm: kworker/u4:0 Not tainted 3.14.0-rc6+ #5 [27.960230] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 [27.960874] Workqueue: tipc_rcv tipc_recv_work [tipc] [27.961430] ffff88003c67f408 ffff88003de27c18 ffffffff815c0207 ffff88003de1c050 [27.962292] ffff88003de27c38 ffffffff815beec5 ffff88003c67f408 ffffffff817f0a8a [27.963152] ffff88003de27c58 ffffffff815beeeb ffff88003c67f408 ffffffffa0013520 [27.964023] Call Trace: [27.964292] [<ffffffff815c0207>] dump_stack+0x45/0x56 [27.964874] [<ffffffff815beec5>] spin_dump+0x8c/0x91 [27.965420] [<ffffffff815beeeb>] spin_bug+0x21/0x26 [27.965995] [<ffffffff81083df6>] do_raw_spin_lock+0x116/0x140 [27.966631] [<ffffffff815c6215>] _raw_spin_lock_bh+0x15/0x20 [27.967256] [<ffffffffa0008540>] subscr_conn_shutdown_event+0x20/0xa0 [tipc] [27.968051] [<ffffffffa000fde4>] tipc_close_conn+0xa4/0xb0 [tipc] [27.968722] [<ffffffffa00101ba>] tipc_conn_terminate+0x1a/0x30 [tipc] [27.969436] [<ffffffffa00089a2>] subscr_conn_msg_event+0x1f2/0x2f0 [tipc] [27.970209] [<ffffffffa0010000>] tipc_receive_from_sock+0x90/0xf0 [tipc] [27.970972] [<ffffffffa000fa79>] tipc_recv_work+0x29/0x50 [tipc] [27.971633] [<ffffffff8105dbf5>] process_one_work+0x165/0x3e0 [27.972267] [<ffffffff8105e869>] worker_thread+0x119/0x3a0 [27.972896] [<ffffffff8105e750>] ? manage_workers.isra.25+0x2a0/0x2a0 [27.973622] [<ffffffff810648af>] kthread+0xdf/0x100 [27.974168] [<ffffffff810647d0>] ? kthread_create_on_node+0x1a0/0x1a0 [27.974893] [<ffffffff815ce13c>] ret_from_fork+0x7c/0xb0 [27.975466] [<ffffffff810647d0>] ? kthread_create_on_node+0x1a0/0x1a0 The recursion occurs when subscr_terminate tries to grab the subscriber lock, which is already taken by subscr_conn_msg_event. We fix this by checking if the request to establish a new subscription was successful, and if not we initiate termination of the subscriber after we have released the subscriber lock. Signed-off-by: Erik Hugne <erik.hugne@ericsson.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-03-06tipc: drop subscriber connection id invalidationErik Hugne
When a topology server subscriber is disconnected, the associated connection id is set to zero. A check vs zero is then done in the subscription timeout function to see if the subscriber have been shut down. This is unnecessary, because all subscription timers will be cancelled when a subscriber terminates. Setting the connection id to zero is actually harmful because id zero is the identity of the topology server listening socket, and can cause a race that leads to this socket being closed instead. Signed-off-by: Erik Hugne <erik.hugne@ericsson.com> Acked-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-03-06tipc: allow connection shutdown callback to be invoked in advanceYing Xue
Currently connection shutdown callback function is called when connection instance is released in tipc_conn_kref_release(), and receiving packets and sending packets are running in different threads. Even if connection is closed by the thread of receiving packets, its shutdown callback may not be called immediately as the connection reference count is non-zero at that moment. So, although the connection is shut down by the thread of receiving packets, the thread of sending packets doesn't know it. Before its shutdown callback is invoked to tell the sending thread its connection has been closed, the sending thread may deliver messages by tipc_conn_sendmsg(), this is why the following error information appears: "Sending subscription event failed, no memory" To eliminate it, allow connection shutdown callback function to be called before connection id is removed in tipc_close_conn(), which makes the sending thread know the truth in time that its socket is closed so that it doesn't send message to it. We also remove the "Sending XXX failed..." error reporting for topology and config services. Signed-off-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Erik Hugne <erik.hugne@ericsson.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-01-14tipc: spelling fixesstephen hemminger
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-06-17tipc: cosmetic realignment of function argumentsPaul Gortmaker
No runtime code changes here. Just a realign of the function arguments to start where the 1st one was, and fit as many args as can be put in an 80 char line. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>